1. Field of the Invention
The invention relates to a high-speed crushing apparatus for finely crushing scrap woods such as branches, leaves, trunks and roots which are produced when trees are trimmed in park, green zone, median strip and the like.
2. Description of the Prior Art
As a crushing apparatus for disposal of scrap woods such as ones from tree, there have heretofore been provided a crushing apparatus which comprises, below a hopper, a hummer part for crushing scrap wood into fragments, a smashing part for further size-reducing the fragments, and a mesh-screening part for adjusting the size of the size-reduced fragments. The apparatus, however, has problems. Firstly, the apparatus cannot work successfully when as the scrap woods are disposed trunks and big branches because they have growth rings. When they are incharged into the apparatus, they are not crushed but are elastically deformed such as a rubber ball, thus bounding and making a noise. Further, when as the scrap woods are disposed flexible small branches, leaves and roots with the apparatus, they can not be crushed successfully. These flexible scrap woods are recognized to be crushed if the crushing apparatus is provided with a thin cutting edge. Such an apparatus, however, involves several disadvantages. Firstly, mounting operation of the thin cutting edge is very difficult from a technical viewpoint. Secondly, its mounting and removing operation involves a risk. Therefore, the apparatus of that kind has not been used.
Referring again to the crushing apparatus (comprising a hummer part for crushing scrap wood into fragments, a smashing part for further size-reducing the fragments, and a mesh-screening part for adjusting the size of the size-reduced fragments), the mesh-screening part tends to get plugged, which results in no practical use. Further, scrap woods usually involve branch, leaf and root having sand and soil attached thereto. In addition, scrap woods may contain gravel admixed thereto. When such scrap woods are disposed with the apparatus, the rotary-type cutting edge and the stationary-type cutting edge thereof are damaged to become dull, thus providing extremely bad workability because the sand, the soil and the gravel are caught and pass between the rotary-type cutting edge and the stationary-type cutting edge or remains before the cutting edges. Therefore, there has been provided no crushing apparatus which can suitably be used for disposal of mass scrap woods cut away from tree.
As such, then scrap woods such as branches, leaves, trunks and roots which are cut away during tree trimming operation in park, green zone, median strip and the like are mass. the scrap woods are carried on trucks and transferred to a dumping ground without crushing the scrap woods. The scrap wood are bulky and, as a result, their carrying efficiency is reduced. Since the scrap wood is green and cannot easily be combusted, it must be subjected to a special treatment prior to dumping on the ground. The cost for the treatment is calculated on the number of the trucks used. If the number is increased, the cost is increased. The bulky scrap woods are costly because they need many trucks.